Last month, the Angolan government did something startling: it announced that an oil deal signed with ChevronTexaco would bring the country $300 million. The disclosure of a single figure may not seem a triumph of transparency, but in the past Angola — like many other countries — treated its oil revenue as a state secret. Revealing its oil payments is the first of many anticorruption measures that Angola desperately needs.

Angola is the second-largest oil producer in sub-Saharan Africa, after Nigeria. Yet its people are by some measures the world's most miserable. These two facts coexist in part because more than $4 billion in oil receipts have disappeared from Angola's treasury in the last six years, according to the International Monetary Fund. That figure is about equal to the government's total social spending for the same period.

The misuse of oil revenues robs Angolans of more than health care and education. The opportunity to steal millions gives the country's leaders a reason never to risk this privilege by democratizing.

In the last few years, countries around the world have agreed to make reforms to promote accountability in the industries that most easily lend themselves to corruption and mismanagement: oil, gas and mining. Angola has not joined them, despite pressures from citizens' groups, oil companies and the monetary fund.

Desperate for loans, Angola has repeatedly agreed to carry out the reforms required by the I.M.F., then violated its promises. When the oil company BP announced in 2001 that it would publish what it paid Angola, the government threatened to cancel its contracts.

Today there is some hope that Angola will begin to use its oil receipts to benefit its people. The end of a 27-year civil war in 2002 deprived the government of its perennial excuse for not improving wretched living conditions. Once dependent on the Soviet Union and Cuba, Angolan officials are now trying to establish relationships with more countries and world institutions. In addition to announcing the ChevronTexaco figure, Angola also released some reports by an international accounting firm hired to track oil revenue, an I.M.F. requirement.

But it should release all the reports in full, audit its state oil company and disclose all information related to its oil income. The I.M.F. has been admirably firm in insisting on these changes. The United States, a buyer of one-third of Angola's oil, has not. When José Eduardo dos Santos, Angola's president, went to Washington last month, Bush administration officials said disappointingly little in public about the need for more transparency. In December, Washington even deemed Angola eligible for trade preferences, based on a set of criteria that are supposed to include corruption-related policies. That was a mistake. Change will come to countries like Angola only if outsiders are resolute about accountability.